Hollow concrete block



A. M. CBAMER. HOLLOW CONCRETE BLOCK.

APPLICATION FILED JUNE 20, 1919.

' 1,41 5,222. I Patented May 9, 1922.

Even/Z011 D AJV- (Fame)- barren stares PATENT ANTON IVLARIUS CBAMER, OE ARENDAL, NORWAY.

HOLLOW CONCRETE BLOCK.

Application filed June 20,

To all 10 7mm it may come rm Be it known that l, AN'roN MARIUs CRAMER, a subject of the King of Norway, and a resident of Arendal, in the Kingdom of Norway, have invented certain new and useful Improvements in Hollow Concrete Blocks; andl do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to the reference numerals marked thereon, which form a part of this specification.

My invention relates to hollow concrete blocks. The object of my invention is to provide blocks having imultaneously with a good interconnection between their inner and outer walls also insulating layers, insulating the outer and inner parts of the blocks completely from each other. In order to effect this I conduct the casting process in two separate operations instead of casting the blocks in one operation as is usually done.

In the following I shall describe my inention referring herewith to the accompanying drawing in which Figure 1 is a horizontal sectional view of a finished block in accordance with my invention and the Figs. 2 and 3 illustrate left and right binding pieces for the same respectively in side elevation. Figure iillustratcs one of the bindingpieces in inside elevation.

First I cast the binding pieces of which two are used for each block in which said binding pieces form the end walls. Figs. 2 and 3 illustrate the binding pieces 1 and 2 for one block as seen from the side. The side faces are provided with dovetail grooves 3, said grooves tapering at the same time inwards against the middle portion of the block. The binding piece 1 is on its outer side or face provided with a tongue l, the edges of which are preferably beveled or inclined, said tongue fitting into a corresponding groove 6 in the binding piece 2 of the adjoining block. Both binding pieces 1 and 2 have on their inside a groove 5 for the Specification of Letters Patent.

Patented May 91, 1195 32.

1919. Serial No. 305,528.

partition or median wall 9. ll hen the bind" ing pieces 1 and 2 have hardened properly their sides which are to be on the outer face of the wall are provided with an insulating coating 17 for instance of tar, asphalt or the like. This coating should preferably reach so far as to also include the outer wall of the grooves 5.

Owing to the dovetail connection between the binc'ling pieces and the outer and inner walls the binding pieces will constitute a reliable inter-connection and at the same time the insulating coating 17 will prevent moisture from entering into the inner part f the block.

I claim as my invention:

1. A hollow concrete building block, comprising concrete end walls having tapering, dovetail grooves in their opposite side faces; a coating of moisture-insulating material extending completely over the surface of each groove, and spaced concrete side walls having their inner fares provided, adjacent the ends thereof, with projections conformably fitting in said coated grooves to rigidly connect said side and end walls together.

2. A hollow concrete building block, comprising concrete end walls having dovetail grooves in their opposite side faces and grooves in their inner end faces; coating of moisture-insulating material extending completely over the surface of each dovetail groove; spaced concrete side walls having their inner faces provided, adjacent the ends thereof, with projections conformablyfitting in the coated grooves in the side faces of the end walls to rigidly connect said side and end walls together; and an intermediate wall arranged in the space between said side walls and fitted its opposite side edges in the grooves in the inner end faces of said end walls.

In. testimony that I claim the foregoing as my invention, have signed my name in presence of two subscribing witnesses.

ANTON MARIUS CRAMER.

W'itnesses OLGA Mt'iLLnR, MAGENS BUGGE. 

